1. Field
Embodiments relate to an aromatic ring-containing polymer, a polymer mixture, an antireflective hardmask composition, and associated methods.
2. Description of the Related Art
There is a continuous demand for minimization in, e.g., the microelectronics industry, including the manufacture of microscopic structures, e.g., micromachines and magneto-resist heads. In the microelectronics industry, there exists a need to reduce the size of microelectronic devices in order to provide a greater number of circuits in a given chip size.
Effective lithographic techniques may be essential to achieve desired minimization. Lithography may affect the manufacture of microscopic structures by, e.g., direct imaging of patterns on particular substrates, and production of masks typically used for such imaging.
A typical lithographic process may involve patternwise exposure of a radiation-sensitive resist to imaging radiation to form a patterned resist layer. Thereafter, an image may be developed by bringing the exposed resist layer into contact with, e.g., an aqueous alkaline developing solution. An underlying layer may then be etched to transfer the pattern to the underlying layer. After completion of the transfer, remaining portions of the resist layer may be removed.
For better resolution in lithographic processes, an antireflective coating (ARC) may be used to minimize reflectivity between an imaging layer, e.g., the radiation-sensitive resist material layer, and the underlying layer. However, since much of the imaging layer may be removed during etching of the ARC after patterning, further patterning may be required in a subsequent etching step.
In other words, in some lithographic imaging processes, the resist material layer may not provide resistance to the subsequent etching step to an extent sufficient to effectively transfer the desired pattern to a layer underlying the resist. In actual applications, e.g., in the case where an extremely thin resist layer is required, an underlying material to be etched is thick, a large etching depth is needed, and/or the use of a particular etchant is required depending on the type of an underlying material, a hardmask layer may be used as an intermediate layer between the patterned resist layer and the underlying material. The hardmask layer may be patterned by transfer from the patterned resist. The hardmask layer should be able to receive the pattern from the patterned resist layer and withstand etching required to transfer the pattern to the underlying material.